Temperature Dependence of Molecular Orientation on the Surfaces of Semi-Fluorinated Polymer Thin Films

Published

February 1, 2000

Author(s)

Jan Genzer, E Sivaniah, E K. Kramer, J G. Wang, H Koerner, K Char, Christopher K. Ober, B M. DeKoven, Robert A. Bubeck, Daniel A. Fischer, S Sambasivan

Abstract

Near-edge X-ray absorption fine structure is used to investigate the temperature dependence of molecular orientation of semi-fluorinated liquid crystalline (SF-LC) mesogens, which are attached to the modified isoprene backbone of i) a polyisoprene homopolymer, and ii) a diblock copolymer consisting of polystyrene and polyisoprene blocks. Our experiments reveal the existence of two temperature regions in which the surface orientation of the SF-LC mesogens changes abruptly. While the lower temperature surface transition seems to be controlled exclusively by the ordering phenomena originating from the surface, the change in the surface organization of the SF-LC mesogens at higher temperatures can be associated with the bulk LC transition from the smectic-A to the isotropic phase.

Citation

Langmuir

Volume

16

Issue

No. 4

Pub Type

Journals

Keywords

co-polymers, fluorinated surfaces, NEXAFS, polymers, thin films

Citation

Genzer, J. , Sivaniah, E. , Kramer, E. , Wang, J. , Koerner, H. , Char, K. , Ober, C. , DeKoven, B. , Bubeck, R. , Fischer, D. and Sambasivan, S. (2000), Temperature Dependence of Molecular Orientation on the Surfaces of Semi-Fluorinated Polymer Thin Films, Langmuir (Accessed September 18, 2024)